An electronic oscillator is an electronic circuit that produces a repetitive output signal. The output signal may be a sinusoid, square wave, or other signal exhibiting a periodic signal characteristic.
Oscillating square waves are often used as clock signals in integrated circuit devices having digital components, or are used with external digital components. In some instances, the frequency of the clock signal is programmable over a predetermined range of frequencies. The stability of the frequency of the clock signal at a given programmed frequency may impact the overall performance of the integrated circuit.
Frequency stability of the clock signal is impacted, among other things, by temperature. One approach to providing temperature stability of the clock signal frequency is to minimize the temperature drift of every circuit component in the oscillator signal path. This approach, however, is sensitive to manufacturing process variations. Another approach involves using a complex phase-lock-loop circuit working in conjunction with an accurate, temperature stable low frequency reference oscillator. The stable, low-frequency oscillator may provide a circuit that is less sensitive to manufacturing process variation than the first noted approach. However, this approach is typically implemented using a large area of the semiconductor material and, further, often requires higher power dissipation.